The present invention concerns a screwdriver for intra-oral implantation with a screwdriver shaft, which, at one end, is connected with a hand piece and at the other end, via an angular gear, with a rotatable tool chuck, that is connected, via a drive shaft located inside the shaft of the screwdriver shaft, with a rotating drive located inside the hand piece.
These types of screwdrivers are used to perform the screwing in processes that must be performed on tooth implants inside the oral cavity, and in particular to perform the screwing in processes that need to be performed to attach implant posts and screws to inserted implants. Due to differences in implant accessibility, so far, different types of screwdrivers of a rigid design have been used for this purpose. In a known screwdriver of the aforementioned type the hand piece is connected, via a straight rigid screwdriver shaft, with a 90xc2x0 angular gear, which is attached to a rotatable tool chuck, into which different types of screwdriver bits can be inserted. Due to the rigid design as a 90xc2x0 angular screwdriver, adaptability is limited; for implants that are difficult to access, still, additional specialized screwdrivers must be held ready and used.
It is therefore an object of this invention to embody a screwdriver of the aforementioned type in such a manner that it would be suited for all screws occurring in intra-oral implants, in particular also in areas of the oral cavity that are difficult to access.
According to the invention, the above and other objects can be achieved by a device wherein the shaft of the screwdriver comprises, at least partly, shaft segments that can be shifted in relation to each other and that, for the purpose of fixing them in their positions, can be tightened up by means of a common tightening device that extends longitudinally. The drive shaft in the area of the shaft segments consists of individual drive shaft pieces, which are connected with each other by means of an angular shaft gear, in the area of each connecting area between two shaft segments, are, for the purpose of torque transmission.
The screwdriver shaft, which is flexible prior to tightening the tightening device, can be bent into a shape that may be optimal for each individual situation and be fixed in this shape, so that the tool chuck can be brought into a position which may be the most advantageous one, as the case may be, even for areas within the patient""s oral cavity that are difficult to access. Accordingly, all tightening tasks which may occur on dental implants can be performed with one single screwdriver, due to its flexible adjustability. The torque between the individual drive shaft segments is transferred in a positive manner and with only very little torsional elasticity.